docs: def _normalize_select(self, query):
          """
          If the query contains the :select operator, we enforce :sys properties.
          The SDK requires sys.type to function properly, but as other of our
          SDKs require more parts of the :sys properties, we decided that every
          SDK should include the complete :sys block to provide consistency
          accross our SDKs.
          """
  
          if 'select' not in query:
              return
  
          if isinstance(
                  query['select'],
                  string_class()):
              query['select'] = [s.strip() for s in query['select'].split(',')]
  
          query['select'] = [s for s
                             in query['select']
                             if not s.startswith('sys.')]
  
          if 'sys' not in query['select']:
              query['select'].append('sys')